head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Practiced Mastery
Isometric co-op puzzling testing coordination and trap-room solutions.

Optimization · Practiced Mastery
Haunted-hotel adventure climbing themed floors with vacuum and goo clone.
Lara Croft and the Temple of Osiris leans Optimization (Practiced Mastery); Luigi's Mansion 3 leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Twin-stick aiming and trap dodging take light skill
Luigi's Mansion 3
Slam combos and boss-dodge timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Enemies swarm on fixed triggers
Luigi's Mansion 3
Floor bosses run fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Puzzle and trap layouts are fixed once seen
Luigi's Mansion 3
Hotel floors are authored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Co-op puzzle solving and score routing lead the test
Luigi's Mansion 3
Gooigi puzzles and gem routes are solvable
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.